Air conditioning apparatus

ABSTRACT

An air conditioning system for cooling or heating an air, and for feeding the heated or cooled air to predetermined portions is characterized by comprising: a first circulating circuit for circulating a first heating medium; a second circulating circuit for circulating a second heating medium; a control unit for controlling the heat for executing heat exchange between the first heating medium and the second heating medium to flow through either the heat exchanger or the first heat storing device. Moreover, an air temperature is controlled by heat of the second heating medium.

TECHNICAL FIELD

This invention relates to an air conditioning system for executing aheat exchange among a plurality of heating mediums, thereby controllingair temperature on the basis of the exchanged heat.

BACKGROUND ART

An air conditioning system for a vehicle is generally constructed toregulate a room temperature by a refrigeration cycle for circulating arefrigerant. The air conditioning system of this kind is disclosed inJapanese Patent Laid-open No. 2000-142078. According to an airconditioning system for a vehicle disclosed in the Laid-open, acompressor, a condenser, a receiver, an expansion valve, an evaporatorand so on are arranged in a circulating circuit of the refrigerant. In acasing of the air conditioning system, a blower fan and an evaporatorare arranged. Moreover, an air inlet and an air outlet are formed on thecasing.

Here will be explained an operation example according to theaforementioned air conditioning system. First of all, when the blowerfan is driven, air is inhaled from the air inlet into the casing. On theother hand, when the compressor is driven by an engine power, therefrigerant is compressed by the compressor and made into ahigh-pressure refrigerant. The compressed and high-pressured refrigerantis then condensed by the condenser and passes through the receiver. Therefrigerant is consequently made into a high-temperature andhigh-pressure liquid refrigerant. This liquid refrigerant is expanded bythe expansion valve, and conveyed to the evaporator in the form of alow-temperature and low-pressure liquid refrigerant. In the evaporator,heat in the air is transferred to the refrigerant due to the temperaturedifference between the air in the casing and the refrigerant, therebyevaporating the liquid refrigerant. The low-temperatured (cooled) air isthen fed from the discharging port to the vehicular room. Therefrigerant passed through the evaporator flows into the compressoragain. Thus, the temperature is regulated in the vehicular room.

“Flow rate of refrigerant” is any one of the conditions which affect theheat transferring capacity of the refrigerant in the circuit. Accordingto the air conditioning system disclosed in the aforementionedLaid-open, since the compressor is driven to transport the refrigerant,the air conditioning function thereof is easily affected by theoperating condition of the compressor. This makes it probable thatnecessary air conditioning function cannot be obtained.

DISCLOSURE OF THE INVENTION

This invention has been made under the aforementioned background, andits object is to provide an air conditioning system in which an airconditioning function is less affected by an operating condition of acompressor for circulating a first heating medium in a first circuit.

More specifically, an object of the invention is to provide an airconditioning system capable of improving fuel consumption by mitigatingan impact on an engine load due to an air conditioning demand, in caseit is mounted on a vehicle.

In order to achieve the aforementioned object, according to the airconditioning system of the invention, a first circuit for circulating afirst heating medium and a second circuit for circulating a secondheating medium are arranged separately from each other. Heat exchangebetween the first and second heating mediums is carried out in a firstheat exchanger, and heat exchange between the second heat medium and airis carried out in a second heat exchanger.

The first heating medium is heated or cooled by using a power unit suchas an engine, motor and the like, and does not exchange heat with air.Therefore, the first heating medium can be heated or cooledindependently from the air conditioning demand. This mitigates directimpact on the load of the power unit due to the air conditioning demand.

According to the invention, moreover, a third heat exchanger, which isdifferent from the first heat exchanger in the heat exchangecharacteristics, is arranged in the circuit which the first heatingmedium flows through. Therefore, it is possible to flow the secondheating medium through the first heat exchanger or the third heatexchanger selectively, so as to execute heat exchange with the firstheating medium. This selection of flow passage is made by operating aselector by a controller. More specifically, in case the airconditioning demand is high, the second heating medium is flown to theheat exchanger having better heat exchange performance than other.

Therefore, the performance of cooling or heating the second heatingmedium can be changed so that the air conditioning can be executed ondemand.

In the first heat exchanger, the flow passage which the first heatingmedium flows through, and the flow passage which the second heatingmedium flows through, are formed adjacent to and in parallel with eachother, and the flowing directions of each heating medium can be madeopposite to each other. With this construction, heat transfer efficiencybetween the heating mediums can be improved.

The third heat exchanger can be constructed of a heat storing devicehaving a heat storage material therein which is heated or cooled by thefirst heating medium. In this case, heat capacity of the third heatexchanger is larger than that of the first heat exchanger. Therefore,the second heating medium is flown to the first heat exchanger toexecute cooling in response to the rapid cooling demand, and the secondheating medium is flown to the third heat exchanger to execute coolingin response to the normal cooling demand, in order to use the storedheat effectively.

According to the invention, furthermore, it is possible to arrange asecond heat storing device, which is heated by receiving heat from thefirst heating medium, and stores the heat therein. For example, as thefirst heating medium, it is possible to adopt a fluid such thattemperature thereof is lowered by pressurizing compression andsubsequent adiabatic expansion. In this case, since the amount of heatof the first heating medium is increased due to the pressurizingcompression, the heat is not discharged to the outside but recovered bythe second heat storing device.

In this invention, the first heat storing device can store heat forcooling, whereas the second heat storing device can store heat forheating. Therefore, it is possible to arrange a control unit for drivinga heat source mechanism for cooling or heating the first heating medium,on the basis of the fact that the amount of heat stored in one or bothof the heat storing devices is lowered.

As has been described above, the first circuit serves as a circuit forgenerating heat for air conditioning, and the second circuit serves as acircuit for cooling or heating air. According to the invention,therefore, it is possible to arrange a control unit for operating thefirst circuit on the basis of temperature of the first heat storingdevice, and for operating the second circuit on the basis of temperatureof air.

In this case, a control of output of a pump for flowing the secondheating medium can be made on the basis of the deviation between the airtemperature in the outlet side of the second heat exchanger and thetarget temperature.

In the heat storing device according to the invention, a number of finsare integrated with a pipe which the heating medium flows through, andthe pipe and fins are embedded in the heat storage material.

The second heat storing device is heated by the first heating medium andraises its temperature. According to the invention, it is possible toarrange a third circuit for circulating a third heating medium betweenthe second heat storing device and a fourth heat exchanger fortransferring heat stored in the second heat storing device.

For heating or cooling the first heating medium of the invention, it ispossible to use a mechanism including a compressor for compressing thefirst heating medium, a heat radiator for radiating heat from thecompressed and high-temperatured first heating medium, and a expanderfor adiabatically expanding the first heating medium. The compressor,the heat radiator and the expander can be connected in series with thefirst heat exchanger and the first heat storing device. The second heatstoring device is preferably connected right behind a discharging portof the compressor. Thus, the heat of the first heating medium is morerecovered by the second heat storing device. As a result, a load on theheat radiator is reduced so that the heat radiator can be downsized. Inaddition, in case of compulsory cooling, energy consumed by a blowingfan can be saved.

Since each heat storing device is adopted to store heat energy forcooling or heating, permission/non-permission of operation of thecompressor can be determined on the basis of their temperature. In thiscase, a hysteresis is set to the permissible temperature and to thenon-permissible temperature.

The first heating medium is compressed to raise its temperature, and isadiabatically expanded to lower it temperature. The second heat storingdevice stores heat of the high-temperatured first heating medium. Thefirst heat storing device is cooled by the adiabatically-expanded andlow-temperatured first heating medium, and stores energy for cooling.Therefore, in case the heat storage capacity of the first heat storingdevice has been saturated, the compressor is not permitted to operateeven if the heat storage capacity of the second heat storing device hasnot been saturated. According to the invention, it is possible toarrange a thawing operation device for heating the first heat storingdevice temporarily.

The duration of the thawing operation can be set on the basis of theroad condition or the running status of the vehicle mounting the airconditioning system thereon.

A prime mover for running can be utilized for driving the compressor. Inthis case, if the prime mover is compulsorily driven by an runninginertia force, it is possible to select a pre-heat storing mode, inwhich the running inertia force can be utilized for driving thecompressor to store heat.

The heat stored in the second heat storing device of the invention canbe utilized for various kinds of applications. In order to regulate theair temperature, for example, the heat may be used for airmix fortransferring heat to the air once cooled by the second heat exchanger.On the other hand, the heat may be used for heating an internalcombustion engine and oil, or for keeping temperature thereof. In casethe heat is used for warming up the internal combustion engine orkeeping temperature thereof, the heat is provided from the second heatstoring device to the internal combustion engine, while the internalcombustion engine is kept halted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptional diagram showing one example of an airconditioning system of the invention.

FIG. 2 is a sectional view showing a construction of a heat storingdevice shown in FIG. 1.

FIG. 3 is an exploded perspective view showing a construction of a heatexchanger shown in FIG. 1.

FIG. 4 is a conceptional diagram showing flowing directions of a brineand a refrigerant in the heat exchanger shown in FIG. 3.

FIG. 5 is a block diagram showing a control line of the air conditioningsystem shown in FIG. 1.

FIG. 6 is a diagram showing a main part of a control flowchart to beapplied to the air conditioning system shown in FIG. 1.

FIG. 7 is a diagram showing a part continuing to the flowchart shown inFIG. 6.

FIG. 8 is a diagram showing one example of a map used in the controlexample shown in FIGS. 6 and 7.

FIG. 9 is a diagram showing a threshold value of temperature judgmentused in the control example shown in FIGS. 6 and 7.

FIG. 10 is a diagram showing another threshold value of temperaturejudgment used in the control example shown in FIGS. 6 and 7.

FIG. 11 is a diagram showing still another threshold value oftemperature judgment used in the control example shown in FIGS. 6 and 7.

FIG. 12 is a diagram showing another example of a map used in thecontrol example shown in FIGS. 6 and 7.

FIG. 13 is a diagram showing another threshold value of temperature usedin the control example shown in FIGS. 6 and 7.

FIG. 14 is a diagram showing still another threshold value oftemperature used in the control example shown in FIGS. 6 and 7.

FIG. 15 is a diagram showing another threshold value of temperature usedin the control example shown in FIGS. 6 and 7.

FIG. 16 is a diagram showing still another threshold value oftemperature used in the control example shown in FIGS. 6 and 7.

BEST MODE FOR CARRYING OUT THE INVENTION

This invention will be described with reference to the accompanyingdrawings. FIG. 1 is a conceptional diagram showing a construction of anair conditioning system A1 for a vehicle. The air conditioning system A1has a first circuit B1, a second circuit C1 and a third circuit D1. Eachcirculation circuit is, specifically, a flow passage for a fluid havinga piping. A refrigerant (e.g., chlorofluorocarbon or refrigerant gascontaining no chlorine) flows through the first circuit B1, whereas abrine (e.g., water or saltwater) flows through the second circuit C1 andthe third circuit D1.

A construction of the first circuit B1 will be described first. Acompressor 1 is arranged in the first circuit B1, which has a suctionport 2 and a discharging port 3. The compressor 1 is driven by an(later-described) engine or an (later-described) electric motor. On theother hand, an outdoor heat exchanger 4 is arranged in the first circuitB1. This outdoor heat exchanger 4 is exemplified by a condenser mountedin front of an engine room. The outdoor heat exchanger 4 has a firstflow port 4A and a second flow port 4B.

A fan 5 for the outdoor heat exchanger 4 is provided. This fan 5 isdriven by the engine or the electric motor. A pressure reducing unit 6and an accumulator 7 is arranged in the first circuit B1. The pressurereducing unit 6 adiabatically expands the compressed refrigerant, and anexpansion valve is adopted as one example. The pressure reducing unit 6has a first flow port 6A and a second flow port 6B. The first flow port6A is communicated with the second flow port 4B of the outdoor heatexchanger 4. Moreover, the accumulator 7 has an inlet 7A and an outlet7B.

On the other hand, there is provided a first heat storing device 8 whichconstitutes a part of the first circuit B1 and a part of the secondcircuit C1, and a second heat storing device 9 which constitutes a partof the first circuit B1 and a part of the third circuit D1. Aconstruction example of the first heat storing device 8 and the secondheat storing device 9 is comprehensively shown in FIG. 2.

The first heat storing device 8 has a casing 10, and is provided withpipes 11 and 12 passing through inside of the casing 10. The pipe 11constitutes a part of the first circuit B1, and the pipe 12 constitutesa part of the second circuit C1. The pipes 11 and 12 are bundled orclosely contacted with each other, and arranged in the casing 10.Therefore, the flow passages for each refrigerant are adjacent to and inparallel with each other.

The pipe 11 has a first flow port 8A and a second flow port 8B servingas inlet and outlet ports of the casing 10. On the other hand, the pipe12 has a first flow port 8C and a second flow port 8D serving as inletand outlet ports to the casing 10. These pipes 11 and 12 are made ofmetal excellent in heat conductivity, e.g., aluminum, copper or thelike.

There are formed plate-like radiation fins 13 on an outer surface of thepipes 11 and 12. A heat storage material 14 is accommodated in thecasing 10. For example, water or the like may be used as the heatstorage material 14. The heat storage material 14 is contacted with thepipes 11 and 12, and each radiation fins 13. An outer surface of thecasing 10 is covered with a heat insulation material 15.

Since the construction of the second heat storing device 9 is almostsimilar to that of the first heat storing device 8, the similar partwill be described with allotting common reference numerals. The secondheat storing device 9 has pipes 11 and 16 passing through inside of thecasing 10. The pipe 11 constitutes a part of the first circuit B1, andthe pipe 16 constitutes a part of the third circuit D1. The pipe 16 ismade of metal excellent in heat conductivity, e.g., aluminum, copper orthe like, and has an inlet port 9A and an outlet port 9B serving asinlet and outlet ports to the casing 10. The inlet port 9A of the secondheat storing device 9 is communicated with the discharging port 3 of thecompressor 1. Moreover, the pipe 11 has an inlet 9C and an outlet 9Dserving as inlet and outlet ports to the casing 10.

A four-way valve 17 is arranged in the first circuit B1. The four-wayvalve 17 selectively communicates or shuts off a route between the firstflow port 8A of the first heat storing device 8 or the first flow port4A of the outdoor heat exchanger 4, and the inlet 7A of the accumulator7 or the second flow port 9B of the second heat storing device 9.

Moreover, there is provided a heat exchanger 18 which constitutes a partof the circuit B1 and a part of the second circuit C1. Specifically, inthe first circuit B1, the heat exchanger 18 is arranged between thepressure reducing unit 6 and the first heat storing device 8. FIGS. 3and 4 illustrates a construction example of the heat exchanger 18. Byarranging a plurality of heat transferring plates 19 in their thicknessdirection, the heat exchanger 18 constitutes a part of the first circuitB1 and a part of the second circuit C1 between the heat transferringplates 19 adjacent to each other.

In the heat exchanger 18, moreover, there are formed a first flow port18A and a second flow port 18B for the first circuit B1, and those portsare communicated with each other. The second flow port 18B iscommunicated with the second flow port 6B of the pressure reducing unit6, and the first flow port 18A is communicated with the first flow port8B of the first heat storing device 8. In the heat exchanger 18,furthermore, there are formed a first flow port 18C and a second flowport 18D for the second circuit C1.

An air conditioning unit 20 is arranged over the second circuit C1 andthe third circuit D1. This air conditioning unit 20 is equipped with aduct 23 having an air intake port 21 and an air discharging port 22. Afan 24, an indoor heat exchanger (or an evaporator) 25 and a heater 26are disposed in the duct 23. The heater 26 has a heater core 35 and adamper 36. Opening degree of the damper 36 is adjustable. The indoorheat changer 25 is arranged between the fan 24 and the heater 26 in theduct 23.

The fan 24 is arranged on the portion closer to the air intake port 21than the indoor heat exchanger 25 and the heater 26, whereas the heater26 is arranged on the portion closer to the air discharging port 22 thanthe fan 24 and the indoor heat exchanger 25. The indoor heat exchanger25 constitutes a part of the second circuit C1, and has an inlet 25A andan outlet 25B. The first flow port 18C of the heat exchanger 18 and thefirst flow port 8C of the first heat storing device 8 are connected inparallel with each other to the inlet 25A. On the other hand, the secondflow port 18D of the heat exchanger 18 and the second flow port 8D ofthe first heat storing device 8 are connected in parallel with eachother to the outlet 25B. The heater 26 constitutes a part of the thirdcircuit D1, and has an inlet 26A and an outlet 26B. The inlet 26A of theheater 26 is communicated with the outlet 9D of the second heat storingdevice 9.

In the second circuit C1, moreover, there is arranged a three-way valve27 for branching a flow passage toward the second flow port 18D of theheat exchanger 18, and the second flow port 8D of the first heat storingdevice 8. The three-way valve 27 selectively communicates or shuts off aroute between the outlet 25B of the indoor heat exchanger 25 and thesecond flow port 8D of the first heat storing device 8 or the secondflow port 18D of the heat exchanger 18. In the second circuit C1,moreover, a first pump 28 is arranged between the outlet 25B of theindoor heat exchanger 25 and the three-way valve 27. This first pump 28has a suction port 28A and a discharging port 28B. The suction port 28Ais connected to the outlet 25B, and the discharging port 28B iscommunicated with the three-way valve 27.

In the third circuit D1, a second pump 29 is arranged between the outlet26B of the heater 26 and the inlet 9C of the second heat storing device9. Both of the first pump 28 and the second pump 29 is avariable-capacitance pump. The second pump 29 has a suction port 29A anda discharging port 29B. The suction port 29A is communicated with theoutlet 26B of the heater 26, and the discharging port 29B iscommunicated with the inlet 9C of the second heat storing device 9.Moreover, there are provided a temperature sensor 30 for detecting theinternal temperature of the first heat storing device 8, a temperaturesensor 31 for detecting the internal temperature of the second heatstoring device 9, and a temperature sensor 32 arranged inside of theduct 23.

A vehicle mounting the aforementioned air conditioning system thereon isexemplified by: a vehicle comprising an internal combustion engine as aprime mover; a vehicle (i.e., a hybrid vehicle) comprising a pluralityof prime movers having different principles of power generation; and avehicle (i.e., an electric vehicle) comprising an electric motor as apower source. For example, in the vehicle having the internal combustionengine, more specifically, having the engine as a power source, anengine power is transmitted to wheels through a transmission. Thevehicle of this kind is controlled by a control line as illustrated inFIG. 5. In short, an electronic control unit 33 is provided as acontroller for controlling the entire vehicle, which is constructed of amicrocomputer composed mainly of a central processing unit (CPU or MPU),a memory unit (RAM and ROM) and an input/output interface. Theinformation detected by the temperature sensors 30, 31 and 32 isinputted to the electronic control unit 33, while various kinds ofsensors 34 detects information such as accelerator opening, enginespeed, fuel injection, suction pipe negative pressure, outside airtemperature, vehicle speed, operating condition of an air conditioningswitch, amount of insolation, shift position, operating condition of anignition key and so on. The various signals of the sensors 34 areinputted to the electronic control unit 33.

From the electronic control unit 33, on the other hand, there areoutputted the signals for controlling the engine 51 and the three-wayvalve 27, the signals for controlling the opening degree of the damper36, the signals for controlling the output of the first pump 28 and thesecond pump 29, and so on. If the compressor 1, the fans 5 and 24 aredriven by the electric motor 50 instead of the engine 51, the signalsfor controlling the drive/stop of the electric motor 50, compressor 1,the fans 5 and 24 are outputted from the electronic control unit 33.

According to the aforementioned air conditioning system A1, it ispossible to switch among three operation modes selectively: a rapidcooling mode, a normal cooling mode (including pre-cold storing mode)and a heating mode. Here will be described controls and actions of theair conditioning system A1 in each selected mode.

(Rapid Cooling Mode)

This rapid cooling mode is selected when the rapid cooling is requiredbecause the room temperature is extremely high, or the amount of heatstored in the first heat storing device 8 is smaller than apredetermined amount. In case the rapid cooling mode is selected, thefour-way valve 17 is kept controlled to communicate the first flow port8A of the first heat storing device 8 and the inlet 7A of theaccumulator 7, and to discommunicate the second flow port 9B of thesecond heat storing device 9 and the first flow port 4A of the outdoorheat exchanger 4.

When the compressor 1 is driven, the refrigerant in the first circuit B1is compressed and discharged form the discharge port 3 in the form of ahigh-temperature and high-pressure gas. The pressurizingly compressedrefrigerant flows into the second heat storing device 9, and heat of therefrigerant is stored in the second heat storing device 9 therebylowering the temperature of the refrigerant. Specifically, the heat ofthe refrigerant is transferred through the pipe 11 and the radiation fin13 to the heat storage material 14, and stored therein. Moreover, thesecond pump 29 is driven to flow the brine through the third circuit D1in the circulating direction G1.

On the other hand, the refrigerant discharged from the second flow port9B of the second heat storing device 9 is conveyed to the outdoor heatexchanger 4. Since an air flow is generated by driving the fan 5, heatis radiated due to the forced-convection in the outdoor heat exchanger 4thereby lowering the temperature of refrigerant and liquefying therefrigerant. The refrigerant thus cooled in the outdoor heat exchanger 4is discharged from the second flow port 4B and conveyed to the pressurereducing unit 6. The refrigerant is adiabatically expanded by passingthrough the pressure reducing unit 6, and then conveyed to the heatexchanger 18.

Here will be described a heat exchanging action between the refrigerantand the brine in the heat exchanger 18. The refrigerant is expanded andthe temperature thereof is lowered in the pressure reducing unit 6 inthe first circuit B1. In the second circuit C1, since the flowages ofthe refrigerant and the brine are divided by the plate 19, heat of thebrine is drawn by the refrigerant and is cooled sufficiently.Specifically, the heat exchanger 8 is constructed of a plurality of theplates 19 arranged in a chassis at a predetermined interval, and thespaces between the plates 19 are made to serve as flow passages. Theseflow passages are connected so as to flow the refrigerant through anyone of the flow passages adjacent to each other across the plate 19, andto flow the brine through the other. Therefore, the flow passages areadjacent to each other in parallel. In the chassis, there are formed anflow inlet and an flow outlet communicating with the flow passage forthe refrigerant, and an flow inlet and an flow outlet communicating withthe flow passage for the brine.

The heat exchanger 18 makes the flowing directions of the refrigerantand the brine opposite to each other. That is, the circulatingdirections of the refrigerant in the first circuit B1 and the brine inthe second circuit C1 are made opposite to each other. This constructionaims at enhancing cooling effect of the brine, by setting the positionin the flowing direction of the refrigerant where it can exert the mosteffective cooling action, at the position where the brine comes out ofthe heat exchanger 18, taking into account that the cooling action ofthe refrigerant deteriorates gradually and heat loss occurs in the heatexchanger 18, as the refrigerant moves the second flow inlet 18B to thefirst flow inlet 18A.

As described above, the refrigerant passed through the heat exchanger 18is introduced into the compressor 1 through the first heat storingdevice 8. Thus, the refrigerant circulates in the first circuit B1. Incase the rapid cooling mode has been selected, the refrigerant flows inthe circulating direction F1 in the first circuit B1.

On the other hand, the three-way valve 27 is kept controlled to connectthe outlet 28B of the first pump 28 and the second flow port 18D of theheat exchanger 18. By driving the first pump 28, the brine in the secondcircuit C1 is cooled by the refrigerant when passing through the heatexchanger 18. After this, the brine in the second circuit C1 is conveyedto the indoor heat exchanger 25 of the air conditioning unit 20. Thus,if the rapid cooling mode has been selected, the refrigerant flows in acirculating direction E1 in the second circuit C1.

In the air conditioning unit 20, on the other hand, the fan 24 is beingdriven, and the air taken from the air suction port 21 is fed to avehicular room X1 from the air discharging port 22 through the duct 23.When the inside air of the duct 23 is passing through the indoor heatexchanger 25, heat of the air is transferred to the brine therebycooling the air, and the temperature of the brine is raised. Thus, thetemperature in the vehicular room X1 is lowered. The brine flows throughthe third circuit D1 also in the rapid cooling mode; however, since thedamper 36 of the heater 26 is closed, the heat exchange is not carriedout between the brine in the third circuit D1 and the air flowing in theduct 23.

(Normal Cooling Mode)

This normal cooling mode is selected to execute cooling in case heat hasbeen stored in the first heat storing device 8 more than thepredetermined amount. In case the normal cooling mode is selected, thefirst circuit B1 and the third circuit D1 fall into same conditions asthat in the rapid cooling mode. In the second circuit C1, on the otherhand, the three-way valve 27 is controlled to communicate the outlet 28Bof the first pump 28 and the second flow port 8D of the first heatstoring device 8, and to shut off a route between the outlet 28B of thefirst pump 28 and the second flow port 18D of the heat exchanger 18. Asa result, the brine discharged from the first pump 28 is conveyed to thefirst heat storing device 8 through the three-way valve 27. In the firstheat storing device 8, heat exchange is carried out between thelow-temperatured refrigerant in the first circuit B1 and the brineflowing in the second circuit C1.

As shown in FIG. 2, the first heat storing device 8 is provided with theheat storage material 14. The heat of the brine is drawn by the heatstorage material 14 and the brine is thereby cooled sufficiently. Asshown in FIG. 2, moreover, the refrigerant and the brine flow in theopposite directions to each other. That is, the circulating direction F1of the refrigerant in the first circuit B1 and a circulating directionH1 of the brine in the second circuit C1 are made opposite to eachother. This construction aims at enhancing cooling effect of the brine,by setting the position in the flowing direction of the refrigerantwhere it can exert the most effective cooling action, at the positionwhere the brine comes out of the heat exchanger 18, taking into accountthat the cooling action of the refrigerant deteriorates gradually andheat loss occurs in the first heat storing device 8, as the refrigerantmoves from the second flow outlet 8B to the first flow outlet 8A.

In this embodiment, even in the normal cooling mode, the refrigerant inthe first circuit B1 is introduced into the first heat storing device 8through the heat exchanger 18. However, in the normal cooling mode, therefrigerant in the first circuit B1 can be introduced into the firstheat storing device 8 without passing through the heat exchanger 18(i.e., bypassing the heat exchanger 18). With this construction, thetransporting route for the refrigerant is shortened so that thenecessary energy to drive the compressor 1 for generating thetransportation force for the refrigerant can be saved, and fuelconsumption of the engine is improved.

Thus, the brine cooled by the first heat storing device 8 is dischargedfrom the first flow port 8C of the first heat storing device 8, and thenconveyed to the air conditioning unit 20. Rest of actions and controlsnot described above are same as those in the rapid cooling mode. Thus,in case the normal cooling mode is selected, the brine flows through thesecond circuit C1 in the circulating direction H1. Descriptions of thepre-cold storage mode will be omitted.

(Heating Mode)

In case the heating mode is selected, the four-way valve is controlledto communicate the first flow port 8A of the first heat storing device 8and the second flow port 9B of the second heat storing device 9, and tocommunicate the inlet 7A of the accumulator 7 and the second flow port4A of the outdoor heat exchanger 4. The three-way valve 27 is controlledto communicate the discharging port 28B of the first pump 28 and thesecond flow port 8D of the first heat storing device 8, and todiscommunicate the discharging port 28B of the first pump 28 and thesecond flow port 18D of the heat exchanger 18. The first pump 28 and thesecond pump 29 are driven, and the damper 36 of the heater 26 is opened.

In case the heating mode is selected, the refrigerant in the firstcircuit B1 is compressed by the compressor 1 and made into ahigh-temperature and high-pressure gas. The refrigerant is then conveyedto the second heat storing device 9. When the refrigerant is conveyed tothe second heat storing device 9, heat of the refrigerant is transferredto the brine in the third circuit D1. Specifically, the heat of therefrigerant is transferred to the brine through the pipe 11, theradiation fin 13, the heat storage material 14 and the pipe 16.Moreover, the refrigerant is sucked into the compressor 1 through theheat exchanger 18, the pressure reducing unit 6, the outdoor heatexchanger 4 and the accumulator 7. In case the heating mode is selected,as has been described above, the refrigerant flows through the firstcircuit B1 in a circulating direction J1.

In the second circuit C1, on the other hand, the brine flows from thedischarging port 28B of the first pump 28 toward the first heat storingdevice 8 by driving the first pump 28. Then, in the first heat storingdevice 8, the heat of the refrigerant is transferred to the brine in thesecond circuit C1 and the brine is thereby heated. Specifically, theheat of the refrigerant is transferred to the brine through the pipes 11and 12, the radiation fin 13 and the heat storage material 14. Thishigh-temperatured brine is discharged from the first flow port 8C of thefirst heat storing device 8 and transported to the indoor heat exchanger25 of the air conditioning unit 20. When the air flowing in the duct 23is passing through the indoor heat exchanger 25, the heat of the brineis transferred to the inside air of the duct 23, and the heated air isfed from the air discharging port 22 to the vehicular room X1. Thus, thevehicular room X1 is heated. The heat discharged from the outlet port25B of the indoor heat exchanger 25 is then sucked into the suction port28A of the first pump 28.

In case the heating mode is selected, the second pump 29 is driven inthe third circuit D1, and the brine flows through the third circuit D1in the circulating direction G1. Therefore, the brine, of which thetemperature is raised in the second heat storing device 9, is conveyedto the heater 26. In the heater 26, heat of the brine is transferred tothe air in the duct 23, and the air in the duct 23 is further heated.The heat discharged from the outlet 26B of the heater 26 is sucked intothe suction port 29A of the second pump 29.

Here will be described a comprehensive control example includingselection among the aforementioned three operation modes, with referenceto the flowcharts shown in FIGS. 6 and 7. Each portion designated by acircled number in the flowchart shown in FIG. 6 continues to a controlroutine designated by corresponding circled number in FIG. 7. To start,referring to the flowchart shown in FIG. 6, it is judged (at Step S601)whether or not a demand to activate the air conditioning system A1 ismade. If the air conditioning switch has been turned on, for example,the answer of Step S601 is YES, and then it is judged (at Step S602)whether or not the rapid cooling demand is made.

The judgment at Step S602 is made on the basis of, for example, the mapshown in FIG. 8 and the diagram shown in FIG. 9. The map of FIG. 8 showsthe correspondence between the temperature of the heat storage material14 of the first heat storing device 8 and the cooling/heating conditionof the heat storage material 14. The map of FIG. 8 illustrates that theheat storage material 14 is in a solid state when the temperaturethereof is at or lower than T2, that the heat storage material 14 is ina mixed state of solid and liquid when the temperature thereof is at T2,and that the heat storage material 14 is in a liquid state or in a mixedstate of liquid and gas when temperature thereof is over T2.

As shown in the diagram of FIG. 9, in case the temperature of the heatstorage material 14 of the first heat storing device 8 is rising, therapid cooling demand is OFF when temperature of the heat storagematerial 14 is at or lower than T6. In case the temperature of the heatstorage material 14 of the first heat storing device 8 reaches T6 orhigher, the rapid cooling demand is ON. On the other hand, in case thetemperature of the heat storage material 14 of the first heat storingdevice 8 is lowering, the rapid cooling demand is ON when thetemperature of the heat storage material 14 exceeds T2, and the rapidcooling demand is OFF when the temperature of the heat storage material14 is at or lower than T2. Thus, the hysteresis is set on the thresholdvalues T2 and T6 for the temperature. It is also possible to judgewhether or not the rapid cooling demand is made by measuring the ambienttemperature around the vehicle or in the vehicular room, and based onwhether or not the measured temperature is higher than the predeterminedvalue.

If the answer of Step S602 is YES, the rapid cooling mode is selected.Then, the four-way valve 17 and the three-way valve 27 are controlledinto the state corresponding to the rapid cooling mode, and also, thefirst pump 28 and the second pump 29 are driven (at Step S604), and theroutine advances to Step S605.

At Step S605, it is judged whether or not the cold storage deficiencyjudgment of the first heat storing device 8 is ON, on the basis of FIGS.8 and 10. “Cold storage deficiency” means that “the temperature of theheat storage material 14 has not been lowered to the predetermined valueor lower”. As shown in the diagram of FIG. 10, for example, in case thetemperature of the heat storage material 14 is rising, the cold storagedeficiency judgment is OFF when the temperature of the heat storagematerial 14 is at or lower than T5, and the cold storage deficiencyjudgment is ON when the temperature of the heat storage material 14exceeds T5. On the other hand, in case the temperature of the heatstorage material 14 is lowering, the cold storage deficiency judgment isON when the temperature of the heat storage material 14 exceeds T2, andthe cold storage deficiency judgment is OFF when the temperature of theheat storage material 14 is at or lower than T2.

If the answer of Step S605 is YES, the amount of heat stored in the heatstorage material 14 is not sufficient. The air conditioning prioritydemand is ON at Step S606, and the routine advances to Step S608. On theother hand, if the answer of Step S605 is NO, the amount of heat storedin the heat storage material 14 is sufficient. The air conditioningpriority demand is OFF at Step S607, and the routine advances to StepS608. “Air conditioning priority demand” means that “it is permitted todrive the compressor 1 regardless of the engine load condition, if theamount of heat stored in the first heat storing device 8 in case ofexecuting the cooling operation by using the first heat storing device 8as a heat source, or the amount of heat stored in the second heatstoring device 9 in case of carrying out the heating operation by usingthe second heat storing device 9 as a heat source, is insufficient withrespect to each air conditioning demand, and the air conditioning cannotbe executed sufficiently”.

At Step S608, it is judged whether or not the cold storage of the firstheat storing device 8 has been completed, on the basis of the map ofFIG. 8 and the diagram of FIG. 11. “Cold storage completion” means that“the temperature of the heat storage material 14 is lowered at or lowerthan the predetermined temperature”. For example, in case thetemperature of the heat storage material 14 is rising, the cold storagecompletion judgment is ON when the temperature of the heat storagematerial 14 is at or lower than T2, and the cold storage completionjudgment is OFF when the temperature of the heat storage material 14exceeds T2. On the other hand, in case the temperature of the heatstorage material 14 is lowering, the cold storage completion judgment isOFF when the temperature of the heat storage material 14 exceeds T1, andthe cold storage completion judgment is ON when the temperature of theheat storage material 14 is at or lower than T1. Thus, the hysteresis isset to the threshold values T1 and T2 for the temperature.

If the answer of Step S608 is YES, it is judged (at Step S609) whetheror not the heat storage completion judgment of the second heat storingdevice 9 is ON, on the basis of the map of FIG. 12 and the diagram ofFIG. 13. “Heat storage completion” means that “the temperature of theheat storage material 14 is raised higher than the predeterminedtemperature”. The map of FIG. 12 shows the corresponding relationbetween the temperature of the heat storage material 14 in case ofutilizing sensible heat of a liquid phase, and the cooling/heatingcondition. Specifically, the target temperature of the cold storage isset between T8 and T9, i.e., between the melting point and the boilingpoint of the heat storage material 14.

In case the temperature of the heat storage material 14 is rising, theheat storage completion judgment is OFF when the temperature of the heatstorage material 14 is at or lower than T9, and the heat storagecompletion judgment is ON when the temperature of the heat storagematerial 14 exceeds T9. On the other hand, in case the temperature ofthe heat storage material 14 is lowering, the heat storage completionjudgment is ON when the temperature of the heat storage material 14exceeds T8, and the heat storage completion judgment is OFF when thetemperature of the heat storage material 14 is at or lower than T8.Thus, the hysteresis is set to the threshold values T8 and T9 for thetemperature.

If the answer of Step 609 is YES, the operation permission of thecompressor 1 is OFF (at Step S610), and the routine advances to StepS618. On the other hand, if the answer of Step S608 is NO, the operationpermission of the compressor 1 is ON (at Step S611), and the routineadvances to Step S618.

On the other hand, if the answer of Step S609 is NO, the operationpermission of the compressor 1 is ON at Step S612, and it is judged atStep S613 whether or not the heat storage material 14 of the second heatstoring device 9 is being thawed (i.e., under the thawing operation). Ifthe answer of Step S613 is NO, the thawing operation is started at StepS616, and a timer 1 is started at Step S617. As illustrated in FIG. 1,in case the thawing operation is started, the heat storage material 14is thawed by temporarily switching the circulating direction of therefrigerant in the first circuit B1 to the same circulating direction asthat in the heating mode (i.e., the circulating direction J1 in FIG. 1),under such a condition that the cooling load is low, and that heatstorage material 14 of the first heat storing device 8 is entirelysolidified and the cold storage has been completed, when the refrigerantis flowing through the first circuit B1 in the circulating direction F1to execute cooling operation.

If the answer of Step S613 is YES, it is judged (at Step S614) whetheror not the timer 1 has timed out. For example, the necessary time untilthe heat storage material 14 is liquefied is determined from thetemperature of the heat storage material 14 in the second heat storingdevice 9, and the timer 1 is set on the basis of the determinationresult.

If the answer of Step S614 is YES, the thawing operation is OFF at StepS615. Also, the circulating direction of the refrigerant in the firstcircuit B1 is returned to the circulating direction corresponding to thecooling mode (i.e., the circulating direction F1 in FIG. 1), and theroutine advances to Step S618. On the other hand, if the answer of StepS614 is NO, the routine advances to Step S618 as it is.

If the answer of Step S618 is YES, the routine advances to Step S619.The first pump 28 is halted and the routine returns to Step S601. On thecontrary, if the answer of Step S618 is NO, the first pump 28 is drivenafter the output thereof is set as follows. First of all, the first pump28 is subjected to on/off control, and the heating capacity iscontrolled by adjusting the opening degree of the damper 36 of theheater core 35. The output of the first pump 28 is so controlled thatthe air temperature TE at the downstream side of the air dischargingport 22 in the air flowing direction reaches a target temperature TEO.During the cooling operation, therefore, when the substantial airtemperature in the vehicular room X1 is higher than the targettemperature, a control is made to increase the flow rate of the firstpump 28. On the other hand, when the substantial air temperature in thevehicular room X1 is at or lower than the target temperature, a controlis made to reduce the flow rate of the first pump 28. During the heatingoperation, on the contrary, when the substantial air temperature in thevehicular room X1 is higher than the target temperature, a control ismade to reduce the flow rate of the first pump 28. On the other hand,when the substantial air temperature in the vehicular room X1 is at orlower than the target temperature, a control is made to increase theflow rate of the first pump 28.

Thus, when executing the control of flow rate of the first pump 28, a P1control may be made to feedback the substantial air temperature in thevehicular room X1 to the target temperature. The following is oneexample of formulas for calculating the flow rate of each pump used forthe P1 control.

(During the Cooling Operation)En=TE−TEOP1out=P1out(n−1)+Kp((E(n)−E(n−1))+(T/Ti*E(n))(During the Heating Operation)En=TE−TEOP1out=P1out(n−1)−Kp((E(n)−E(n−1))+(T/Ti*E(n))

In the above formulas: P1out is the output of the first pump 28; TE isthe substantial air temperature; TEO is the target temperature; E is thedeviation between the air temperature and the target temperature; KP isthe proportional constant; Ti is the integral constant; and T is thesampling time.

On the other hand, if the air conditioning switch has been turned offwhen making the judgment at Step S601 in FIG. 6, the answer of Step S601is NO and the routine advances to FIG. 7. Then, it is decided (at StepS621) whether or not the heating demand is ON. The judgment at Step S621is made on the basis of the diagram of FIG. 14. For example, in case thetarget temperature of the air blowing from the air discharging port 22of the air conditioning unit 20 (i.e., a necessary blow temperature TAO)is rising, the heating demand is OFF when the necessary blow temperatureis at or lower than T45. On the other hand, the heating demand is ONwhen the necessary blow temperature exceeds T45. On the contrary, incase the necessary blow temperature is lowering, the heating demand isON when the necessary blow temperature exceeds T45. On the other hand,the heating demand is OFF when the necessary blow temperature is at orlower than T35. Thus, the hysteresis is set to the threshold values T35and T45 for the temperature.

If the answer of Step S621 is YES, the heating mode is selected, and thefirst pump 28 and the second pump 29 are driven (at Step S622). Then, itis judged (at Step S624) whether or not the heat storage deficiencyjudgment of the first heat storing device 8 is ON, on the basis of themap of FIG. 8 and the diagram of FIG. 10. “Heat storage deficiency”means that “the temperature of the heat storage material 14 has not beenraised higher than the predetermined temperature”. As shown in FIG. 15,for example, in case the temperature of the heat storage material 14 isrising, the heat storage deficiency judgment is ON when the temperatureof the heat storage material 14 is at or lower than T4, whereas the heatstorage deficiency judgment is OFF when the temperature of the heatstorage material 14 exceeds T4. On the other hand, in case thetemperature of the heat storage material 14 is lowering, the heatstorage deficiency judgment is OFF when the temperature of the heatstorage material 14 exceeds T7, and the heat storage deficiency judgmentis ON when the temperature of the heat storage material 14 is at orlower than T7. Thus, the hysteresis is set to the threshold values T4and T7 for the temperature.

If the answer of Step 624 is YES, the air conditioning priority demandis ON (at Step S625), and the routine advances to Step S627. On thecontrary, if the answer of Step 624 is NO, the air conditioning prioritydemand is OFF (at Step S626), and the routine advances to Step S627. AtStep S627, it is judged whether or not the heat storage completionjudgment of the first heat storing device is ON, on the basis of the mapof FIG. 8 and the diagram of FIG. 16.

As shown in FIG. 16, for example, in case the temperature of the heatstorage material 14 is rising, the heat storage completion judgment isOFF when the temperature of the heat storage material 14 is at or lowerthan T4, whereas the heat storage completion judgment is ON when thetemperature of the heat storage material 14 exceeds T4. On the otherhand, in case the temperature of the heat storage material 14 islowering, the heat storage completion judgment is ON when thetemperature of the heat storage material 14 exceeds T3, whereas the heatstorage completion judgment is OFF when the temperature of the heatstorage material 14 is at or lower than T3.

If the answer of Step S627 is YES, the operation permission of thecompressor is OFF (at Step S628), and the routine advances to Step S630.On the contrary, if the answer of Step S627 is NO, the operationpermission of the compressor is ON (at Step S629), and the routineadvances to Step S630.

The following formula is set at Step S630.TEO=TAO

TAO is the target (required) temperature of the air being dischargedfrom the air discharging port 22. Subsequently to Step S630, the outputsof the first pump 28 and the second pump 29 are calculated (at StepS631), and the routine returns to Step S601 of FIG. 6. The negativeanswer at Step S621 means that neither cooling nor heating is requiredunder that condition.

In this case, the pre-cold storing mode is selected (at Step S623), andthe routine advances to Step S607 of FIG. 6. If the pre-cold storingmode is selected, a control is made to store heat in the heat storingdevice or to radiate heat from the heat storing device by driving thecompressor 1 by a part of the torque of the idling engine 51, under sucha condition that fuel consumption of the engine 51 is nearly unaffected;for example, when the vehicle is running by the inertia force and acontrol is being made to suspend the fuel feeding, the kinetic energygenerated by the inertia running of the vehicle is transmitted to theengine 51 thereby idling the engine 51.

By executing such a control, heat of the first heat storing device 8 isradiated without deteriorating fuel consumption of the engine 51, andthe heat is stored in the second heat storing device 9. Therefore, it ispossible to prepare for next requirement not only of the airconditioning function, but also of the heating operation.

In each Step, when the ignition key is turned on through the accessoryposition, i.e., when the system is activated, various judgments are maderegardless of the temperature of the respective diagrams. In the diagramof FIG. 9, for example, when the system is activated, a rapid coolingdemand judgment is ON. On the other hand, in the diagram of FIG. 10,when the system is activated, the cold deficiency judgment of the firstheat storing device 8 is ON. In the diagram of FIG. 11, when the systemis activated, the cold storage deficiency judgment of the first heatstoring device 8 is OFF. In the diagram of FIG. 13, when the system isactivated, the heat storage completion judgment of the second heatstoring device 9 is OFF. In the diagram of FIG. 14, when the system isactivated, the heating demand judgment is ON. In the diagram of FIG. 15,when the system is activated, the heat storage deficiency judgment ofthe first heat storing device 8 is ON. In the diagram of FIG. 16, whenthe system is activated, the heat storage completion judgment of thefirst heat storing device 8 is OFF. At Step S601 in FIG. 6, it is alsopossible to judge, on the basis of the outside air temperature, whetheror not the activation demand of the air conditioning system A1 is made.

Thus, in the air conditioning system A1 illustrated in FIG. 1, heatexchange is carried out between the refrigerant flowing through thefirst circuit B1 and the brine flowing through the second circuit C1, soas to heat or cool the air. In this embodiment, moreover, there are somedifferences between the heat exchanger 18 and the first heat storingdevice 8 in the heat exchange function, e.g., the heat transfercoefficient, a heat flux, a heat transmission coefficient, a heatresistance or the like. Specifically, the heat exchange function betweenthe refrigerant and the brine of the heat exchanger 18 is higher thanthat of the first heat storing device 8. This is because the heatstoring material 14 is not accommodated in the heat exchanger 18, andthe heat capacity of the first heat storing device 8 is therefore largerthan that of the heat exchanger 18 in which the heat storing material 14is accommodated.

For this reason, in the air conditioning system A1 as shown in FIG. 1,the heat exchange function (or the heat exchange characteristics)between the refrigerant of the first circuit B1 and the brine of thesecond circuit C1 can be changed without changing the refrigeranttransport function of the compressor 1, by selecting either the firstheat storing device 8 or the heat exchanger 18. Therefore, the necessaryair conditioning function can be obtained regardless of the operatingcondition of the compressor 1, thereby controlling the room temperaturearbitrarily.

Moreover, it is less necessary to control the driving condition of thecompressor 1 in accordance with the necessary blow temperature. In otherwords, the impact on the engine load caused by the air conditioningdemand is suppressed. If the compressor 1 is driven by the engine 51,accordingly, fuel consumption of the engine 51 can be improved. On theother hand, if the engine 51 is driven by an electric generator, and theelectric motor 50 is provided with electric energy to drive thecompressor 1, consumption of electric energy is suppressed in theelectric motor 50 so that fuel consumption of the engine 51 can beimproved. That is, the engine load can be equalized regardless of thechange in the necessary blow temperature. Moreover, it is possible tosuppress consumption of a part of power for driving the compressor 1when the engine torque is low, thereby suppressing a degrading ofdrivability.

In the first heat storing device 8 or the heat exchanger 18, moreover,in case the heat storage characteristics of the first heat storingdevice 8, such as a temperature, heat amount or the like, has been readyfor responding to the necessary blow temperature, the heat exchange iscarried out between the brine and the refrigerant through the first heatstoring device 8. Therefore, the mismatch between the necessary blowtemperature and the heat storage characteristics is surely avoided sothat the air conditioning function of the air conditioning system A1 canbe further improved.

Furthermore, heat of the refrigerant flowing through the first circuitB1 can be stored in the second heat storing device 9, and the heat canbe transferred to the air passing through the duct 23. Therefore, it ispossible to enhance usability of the surplus heat energy which isgenerated during the compression by the compressor 1 and not transferredto the heat exchanger 18 and the first heat storing device 8, so thatthe air conditioning function of the air conditioning system A1 can befurther improved.

Conventionally, heat of the condenser 4 is radiated to ambient air.According to this embodiment, the heat of the condenser 4 is stored inthe second heat storing device 9, and the heat energy can be used forairmix during the cooling operation, as a heat source during the heatingoperation, and as a heat source for warming up the engine 51 or heatingoil and so on. The “airmix” means that the air cooled by the indoor heatexchanger 25 is heated by heat of the heater 26 in order to keep thetemperature of the vehicular room X1 in the target temperature. In caseof using the heat as the heat source for warming up the engine 51 orheating the oil and so on, specific embodiments of the case areexemplified as follows:

-   {circle around (1)} A preset condition is satisfied (e.g., the    vehicle is stopped, the accelerator opening is zero, and a brake    pedal is ON) and “idling stop control” to stop the engine 51 is    made.-   {circle around (2)} A hybrid vehicle having the engine 51 and the    electric motor as prime movers is run by a torque of the electric    motor with the engine 51 kept stopped.

Moreover, heat of the high-pressure and high-temperature refrigerant gascompressed by the compressor 1 is drawn by the second heat storingdevice 9, and the refrigerant then is fed to the condenser, therebyreducing heat amount of the refrigerant to be radiated by the condenser.This makes it possible to lower the operation rate of the fan 5, therebyreducing necessary electricity to operate the fan 5. In addition, it isalso possible to improve fuel consumption of the engine 51 for drivingthe electric generator to generate the electricity.

According to the air conditioning system shown in FIG. 1, stillmoreover, in case the rapid cooling mode or the cooling mode isselected, the flowing direction of the refrigerant in the first circuitB1 and the flowing direction of the brine in the second circuit C1 areopposed to each other. Specifically, if the rapid cooling mode isselected, the moving directions of the refrigerant and the brine areopposed to each other in the heat exchanger 18, and if the cooling modeis selected, the moving directions of the refrigerant and the brine areopposed to each other in the first heat storing device 8. For thisreason, the temperature difference between the refrigerant and the brinecan be kept as large as possible in the whole area in the flowingdirections of the refrigerant and the brine. This enhances the heattransfer efficiency in the heat exchanger 18 and the first heat storingdevice 8.

The radiation fin 13 is arranged in the first heat storing device 8 andthe second heat storing device 9. Therefore, the heat transferringcondition can be homogenized in the entire heat storage material 14.This makes it possible to decongest the stress on the heat storagematerial 14, thereby improving durability of the heat storing devices.Moreover, providing the radiation fin 13 increases the heat transferringarea between the refrigerant and the brine, thereby enhancing the heattransfer efficiency.

In case the rapid cooling mode or the cooling mode is selected,moreover, it is possible to store heat of the refrigerant in the secondheat storing device 9 before the refrigerant is conveyed to the outdoorheat exchanger 4. Therefore, the operation rate of the fan 5 for coolingthe refrigerant can be lowered. In the example of FIG. 1, heat of thesecond heat storing device 9 is transferred to the air conditioning unit20. However, if the heat of the second heat storing device 9 is used forwarming-up of the engine 51 at its starting time, the emission abatementmay be improved. This example is applicable to a vehicle having only anengine as a prime mover, a hybrid vehicle having an engine and anelectric motor as a prime mover, and an economy-running vehicle which iscapable of controlling start and halt of the engine on the basis ofpredetermined conditions other than the operating state of the ignitionkey, and so on.

According to the embodiment of FIG. 1, moreover, it is possible to storecold in the first heat storing device 8, and to store heat in the secondheat storing device 9. Under a condition such that both cooling andheating is possible to be used (i.e., in spring or autumn), therefore,the heat preliminarily stored in the second heat storing device 9 can beutilized when the heating operation is required, and the heatpreliminarily stored in the first heat storing device 8 can be utilizedwhen the cooling operation is required. This makes it possible toprevent heat loss.

Still moreover, if heat is stored preliminarily in the second heatstoring device 9 and the first heat storing device 8 by driving thecompressor 1, the air conditioning system A1 can be driven. In thiscase, it is possible to use the stored heat by operating only the firstpump 28 and the second pump 29, without driving the compressor 1.Therefore, fuel consumption and drivability of the engine 51 can beimproved.

Since the stored heat in the second heat storing device 9 can be usedfor airmix at the cooling time, dehumidifying, heating and so on, it ispreferable that the second heat storing device 9 is under the maximumheat storage condition. In the aforementioned flowchart of FIG. 6, forexample, if the routine advances to Step S612 through Step S608 and StepS609, it is preferable to store heat in the second heat storing device 9which can store heat more. However, if the cold storage has beencompleted in the first heat storing device 8, the heat in the first heatstoring device 8 cannot be transferred to the refrigerant in the firstcircuit B1 transported by the compressor 1.

In this case, at Step S616, the heat storage material 14 of the firstheat storing device 8 is temporarily put under the thawing operation soas to transfer the heat of the first heat storing device 8 to therefrigerant in the first circuit B1. Moreover, it is preferable todetermine the preset time of the timer 1 at Step S617 so as to achievesuch a heat capacity as expected.

The expected heat capacity is determined from a road gradientinformation, an infrastructure information (a traffic information,weather information and so on), a vehicle speed, an engine speed, anoutside temperature, an amount of heat necessary for air conditioning ofvehicular room. Also, the expected heat capacity can be set on the basisof the amount of heat stored in the second heat storing device 9.

Here will be described the corresponding relation between theconstruction of embodiments and the present invention. The refrigerantcorresponds to the first heating medium of the invention; the brinecorresponds to the second heating medium according to the invention; theelectronic control unit 33 corresponds to the control unit of theinvention; “the case in which the temperature of the heat storagematerial 14 exceeds a predetermined temperature” corresponds to “thecase in which the predetermined heat is stored in the first heat storingdevice”; the circulating direction F1 of the refrigerant in the firstcircuit B1 corresponds to “the circulating direction of the firstheating medium in the first circuit” and the circulating directions H1and E1 of the brine in the second circuit C1 corresponds to “thecirculating direction of the second heating medium in the secondcircuit”.

The characteristic constructions described in the embodiments areexemplified as follows; specifically, a control unit of an airconditioning system, which executes heat exchange between a heatingmedium and a first heat transfer object by moving the heating medium bya transfer unit or a pressure unit, is characterized by comprising atemperature control demand judging means for judging a temperaturecontrol demand of an object to be air-conditioned, and an selectionmeans for selecting, when the heat exchange is executed between theheating medium and the first heat transfer object, a heat exchanger tobe used from a plurality of heat exchangers having different heatexchange functions respectively and arranged at different positions inthe moving direction of the heating medium.

Moreover, the selection means further comprises a function to select anyone of the plurality of heat exchangers, in case of changing thetemperature of the first heat transfer object for more than apredetermined value, in order to improve the hear exchange functionbetween the heating medium and the first heat transfer object. Stillmoreover, the selection means comprises a function to select any one ofthe plurality of heat exchangers which has had a predetermined functionsuch that the temperature of the first heat transfer object can be setto a predetermined temperature.

Furthermore, there is arranged a heat exchanger for executing heatexchange between the heating medium and a second heat transfer object,if a mechanical energy is applied on the heating medium by the transferunit or the pressure unit thereby changing the temperature of theheating medium. Moreover, the moving direction of the heating medium andthe moving direction of the first heating object are opposite to eachother. Moreover, the heat transferred from the heating medium to thefirst heat transfer object and the heat transferred from the heatingmedium to the second heat transfer object are transferred to sametemperature control object portion. Here, Step S601, Step S602 and StepS621 shown in FIGS. 6 and 7 correspond to the temperature control demandjudging means, and Step S603, Step S604, Step S622 and Step S623correspond to the selection means.

The temperature control demand judging means as described in thecharacterizing part can be read as a temperature control demand judgeror a controller for temperature control demand judgment, and theselection means can be read as a selector or a controller for selection.In this case, the electronic control unit 33 shown in FIG. 5 correspondsto the temperature control demand judger, the controller for temperaturecontrol demand judgment, the selector or the controller for selection.Moreover, the temperature control demand judging means as described inthe characterizing part can be read as a temperature control demanddeciding step, the selection means can be read as a selecting step, andthe control unit for the air conditioning system can be read as acontrol step for the air conditioning system.

As has been described above, according to the air conditioning system ofthe invention, the first heating medium is heated or cooled by using thepower unit such as the engine and the motor, but the first heatingmedium does not execute heat exchange with the air directly. Thisenables the first heating medium to be heated or cooled independentlyfrom an air conditioning demand, so that the direct impact of the airconditioning demand on the load of the power unit can be mitigated. As aresult, fuel consumption of a vehicle mounting the engine can beimproved.

Moreover, a plurality of heat exchangers having different heat exchangecharacteristics respectively is arranged in a circuit which the firstheating medium flows through. The second heating medium flows into anyone of those heat exchangers selectively, and executes heat exchangewith the first heating medium. With this construction, the ability forcooling or heating the second heating medium can be switched therebyexecuting the air conditioning on demand.

If the flowing directions of the first heating medium and the secondheating medium in the heat exchanger are made opposite to each other, itis possible to make the temperature difference between the heatingmediums greater at the outlet side of the second heating medium, therebyheating or cooling the second heating medium efficiently. That is, theheat transfer efficiency between each of the heating mediums can beimproved.

According to the invention, instead of the heat exchanger, a heatexchanger having a heat storing function or a heat storing device may bearranged in the first circuit. In other words, the aforementioned thirdheat exchanger may be replaced by the one having such a heat storingfunction. With this construction, since the heat exchange efficiency ofthe first heat exchanger is high, the rapid cooling demand is fullysatisfied. Moreover, since the heat for cooling can be stored in thethird heat exchanger, the energy efficiency can be improved.

According to the invention, moreover, there may be arranged a secondheat storing device. The second heat storing device is heated byreceiving heat from the first heating medium and stores the heattherein. For example, the first heating medium may be a liquid which isadiabatically expanded after pressurizingly compressed, and thetemperature of which is lowered. In this case, since the amount of heatof the first heating medium is increased due to the pressurizingcompression, the heat is not discharged to outside but recovered by thesecond heat storing device. As a result of this, the energy efficiencycan be improved and fuel consumption of the vehicle is thereby improved.

The heat storing device according to the invention is constructed suchthat a number of fins are integrated with a pipe which the heatingmedium flows through, and the pipe and fins are embedded in the heatstorage material. Therefore, it is possible to increase the heatexchange efficiency between the heat storage material and each of theheating mediums, and to prevent or ease concentration of thermal stressin the heat storing device.

According to the invention, heat of the second heat storing device canbe transferred to air by using the third circuit so that the heatefficiency during heating operation can be improved, and the so-calledairmix can be carried out easily and efficiently.

The second heat storing device is aligned right behind the compressorwhich pressurizes and compresses the first heating medium. Therefore,the amount of heat of the first heating medium to be recovered by thesecond heat storing device is increased. As a result, the load on theheat radiation device is decreased so that the heat radiating device canbe downsized, and energy consumption can be reduced in case of executinga compulsory cooling.

A prime mover for running may be utilized as the prime mover for drivingthe compressor. In that case, if the prime mover is compulsorily drivenby the running inertia force, it is possible to select the pre-heatstoring mode in which heat storage is executed by driving the compressorby the running inertia force. As a result, regenerative energy amount isfurther increased so that fuel consumption of the vehicle can beimproved.

The heat stored in the second heat storing device of the invention canbe used for various applications. In order to regulate the airtemperature, for example, it is possible to use the heat for airmix toprovide heat to the air once cooled in the second heat exchanger. On theother hand, the heat may be used for heating or keeping heat of the oilor the internal combustion engine. Thus, the recovered heat can be usedefficiently so that the fuel consumption of the vehicle is improved, andthe emission can be reduced.

INDUSTRIAL APPLICABILITY

This invention can be utilized in the industrial field where airconditioning of a room, a working space and so on is executed, and asystem therefor is manufactured. Moreover, this invention can beutilized in the field where a stationary air conditioning system or amobile air conditioning system mounted on a vehicle is used ormanufactured.

1. An air conditioning system for cooling or heating an air, and forfeeding the heated or cooled air to predetermined portions, comprising:a first circulating circuit circulating a first heating medium; a secondcirculating circuit circulating a second heating medium; a first heatexchanger executing heat exchange between the first and second heatingmedia; a second heat exchanger for executing heat exchange between thesecond heating medium and the heated or cooled air; a compressorpressurizing the first heating medium; an expander distributing thepressurized first heating medium, connected with the first heatexchanger; a first heat storing device having a storing material whichis heated or cooled by the first heating medium, executing heat exchangeamong the first heating medium, the second heating medium, and the heatstoring material; a three-way valve arranged in the second circulatingcircuit and connected with the first heat exchanger, the first heatstoring device, and the second heat exchanger; a controller connectedwith the three-way valve and executing a switching operation of thethree-way valve on the basis of an air conditioning demand, thecontroller comprising a microcomputer having a central processing unit,a memory unit, an input, and an output; and a pump pressurizing andflowing the second heating medium; wherein the controller comprises ameans for controlling an output of the pump on the basis of a deviationbetween the air temperature and a target temperature at a predeterminedposition in the outlet side of the second heat exchanger; wherein thesecond circulating circuit comprises a first sub-circuit flowing thesecond heating medium through the first heat exchanger, a secondsub-circuit flowing the second heating medium through the first heatstoring device, and the three-way valve communicating the second heatexchanger selectively to the first sub-circuit and the secondsub-circuit; wherein the first heat exchanger is arranged on an upstreamside of the first heat storing device in a flowing direction of thelow-temperatured first heating medium; wherein the three-way valveexecutes a switching operation to flow the second heating medium intothe first heat exchanger through the first sub-circuit in case the rapidcooling is demanded, and executes a switching operation to flow thesecond heating medium into the first heat storing device through thesecond sub-circuit in case the normal cooling is demanded; wherein asecond heat storing device having a heat storage material which receivesheat from the first heating medium and stores the heat therein isarranged in the first circulating circuit; and wherein the controlleroperates the first circulating circuit in accordance with a temperatureof at least one of the first and second heat storing devices andoperates the second circulating circuit in accordance with the airtemperature.
 2. The air conditioning system according to claim 1,wherein: the controller controls a switching operation of the three-wayvalve so as to flow the second heating medium through a selected one ofthe first heat exchanger and the first heat storing device, when the airconditioning demand increases.
 3. The air conditioning system accordingto claim 1, wherein: the first heat exchanger comprises a first flowpassage flowing the first heating medium, and a second flow passageformed adjacent to and in parallel with the first flow passage andflowing the second heating medium; and a flowing direction of the firstheating medium in the first flow passage and a flowing direction of thesecond heating medium in the second flow passage are opposite to eachother.
 4. The air conditioning system according to claim 1, furthercomprising: a heat source mechanism, including said compressor, heatingand cooling the first heating medium; wherein the controller operatesthe heat source mechanism, in case the temperature of the heat storagematerial in at least any one of the heat storing devices is at apredetermined value or lower, and air conditioning is demanded.
 5. Theair conditioning system according to claim 1, wherein: at least one ofthe first heat storing device and the second heat storing devicecomprises a pipe penetrating the heat storage material flowing the firstheating medium or the second heating medium therethrough, and aplurality of fins embedded in the heat storage material and integratedwith the pipe.
 6. The air conditioning system according to claim 1,wherein: the second heat storing device is arranged on an upstream sideof the first heat storing device in a flowing direction of the firstheating medium.
 7. The air conditioning system according to claim 1,further comprising: a third heat exchanger executing heat exchangeselectively with the air; and a third circuit circulating a thirdheating medium between the second heat storing device and the third heatexchanger, and providing heat to the third heating medium in the secondheat storing device.
 8. The air conditioning system according to claim1, further comprising: a determining device determining permission andnon-permission of operation of the compressor on the basis of thetemperature of the heat storage material in either the first heatstoring device or the second heat storing device; wherein a hysteresisis set to the permissible temperature and non-permissible temperature ofoperation of the compressor.
 9. The air conditioning system according toclaim 1, further comprising: a thawing device heating the first heatstoring device temporarily; wherein the first heat storing device storesenergy for cooling, and the second heat storing device stores heat forheating.
 10. The air conditioning system according to claim 9, wherein:the air conditioning system is mounted in a vehicle; and wherein thethawing device comprises a means for setting the amount of heat forheating the first heat storing device on the basis of at least one of aroad information on which the vehicle is running, weather around thevehicle, a vehicle speed, an engine speed, outside temperature, and anamount of heat necessary to air condition the room.
 11. The airconditioning system according to claim 10, further comprising: a primemover outputting a power, which runs the vehicle and, that drives thecompressor; wherein the controller selects a pre-heat storing mode, inwhich heat is stored in the first heat storing device or radiated bydriving the compressor by a running inertia force, when the prime moveris driven compulsorily by the running inertia force.
 12. The airconditioning system according to claim 1, further comprising: a selectorvalve switching a flowing direction of the first heating medium, into adirection from the compressor through a heat radiator and the expanderto the first heat storing device, and into a direction from a heaterthrough the first heat storing device and the expander to the heatradiator.
 13. The air conditioning system according to claim 12,wherein: the second heat storing device, which receives heat from thefirst heating medium and stores the heat therein, is arranged between adischarging port of the compressor and the selector valve.
 14. The airconditioning system according to claim 13, further comprising: a thirdheat exchanger executing heat exchange selectively with the air; and athird circulating circuit circulating a third heating medium between thesecond heat storing device and the third heat exchanger, and providingheat to the third heating medium in the second heat storing device. 15.The air conditioning system according to claim 1, further comprising: anair mix executing device providing heat of the second heat storingdevice to the air cooled by the second heat exchanger, thereby heatingthe air.
 16. An air conditioning system for cooling or heating an air,and for feeding the heated or cooled air to predetermined portions,comprising: a first circulating circuit circulating a first heatingmedium; a second circulating circuit circulating a second heatingmedium; a first heat exchanger executing heat exchange between the firstand second heating media; a second heat exchanger for executing heatexchange between the second heating medium and the heated or cooled air;a compressor pressurizing the first heating medium; an expanderdistributing the pressurized first heating medium, connected with thefirst heat exchanger; a first heat storing device having a heat storingmaterial which is heated or cooled by the first heating medium,executing heat exchange among the first heating medium, the secondheating medium, and the heat storing material; a three-way valvearranged in the second circulating circuit and connected with the firstheat exchanger, the first heat storing device, and the second heatexchanger; a controller connected with the three-way valve and executinga switching operation of the three-way valve on the basis of an airconditioning demand, the controller comprising a microcomputer having acentral processing unit, a memory unit, an input, and an output; asecond heat storing device having a heat storage material which receivesheat from the first heating medium and stores the heat therein isarranged in the first circulating circuit; and at least one of aninternal combustion engine and a drive unit having oil; wherein thecontroller provides heat stored in the second heat storing device to anyone of the internal combustion engine or the drive unit, therebyexecuting either warming up of the internal combustion engine or heatingof the oil; wherein the second circulating circuit comprises a firstsub-circuit flowing the second heating medium through the first heatexchanger, a second sub-circuit flowing the second heating mediumthrough the first heat storing device, and the three-way valvecommunicating the second heat exchanger selectively to the firstsub-circuit and the second sub-circuit; wherein the first heat exchangeris arranged on an upstream side of the first heat storing device in aflowing direction of the low-temperatured first heating medium; andwherein the three-way valve executes a switching operation to flow thesecond heating medium into the first heat exchanger through the firstsub-circuit in case the rapid cooling is demanded, and executes aswitching operation to flow the second heating medium into the firstheat storing device through the second sub-circuit in case the normalcooling is demanded.
 17. The air conditioning system according to claim16, wherein: the controller operates a first circulating circuit inaccordance with a temperature of at least one of the heat storingdevices and operates the second circulating circuit in accordance withthe air temperature.
 18. The air conditioning system according to claim16, further comprising: a means for warming up the internal combustionengine by the heat of the second heat storing device, while the internalcombustion engine is halted.